// struct spinlk {
//     int lk;
// };

struct sleeplk {
    int lk;
};

#define SLEEPLK_BARRER(slk) {while (!slk.lk);} 

// void spin_lock (struct spinlk * spnlk);

// void spin_unlock (struct spinlk * spnlk);

void sleep_lock (struct sleeplk * slplk);

void sleep_unlock (struct sleeplk * slplk);